Endoscopic spine surgery nomenclature: A call for global consensus

First published online by Sage in the Global Spine Journal, October 26, 2026. Kim J-S (Luke), Kotheeranurak V, Heo D-H, Taha MM. Toward a Unified Nomenclature for Endoscopic Spine Surgery: A Call for Multi-Society Consensus. doi:10.1177/21925682261497330 Republished under the Creative Commons CC-BY-NC-ND license. 

Introduction

Over the past decade, endoscopic spine surgery has moved well beyond its origins in lumbar discectomy. It is now used across the cervical, thoracic, and lumbar spine for procedures that once required open or microscopic techniques. In 2020, an international group of surgeons published the AO Spine consensus on nomenclature for working-channel endoscopic spinal procedures, which brought order to a rapidly expanding field by organizing terms by endoscope type (full-endoscopic versus endoscope-assisted), approach corridor, spinal segment, and type of procedure. 

That paper classified endoscopic spine surgery into full-endoscopic—that is, working-channel—and endoscope-assisted procedures, placing biportal endoscopy within the endoscope-assisted category. The four-part logic it introduced remains the right foundation on which to specify how biportal visualization and endoscopic fusion should now be named. In the years since, reviews and bibliometric analyses have documented how quickly the field has grown, how far its indications have expanded, and how large its literature has become. 

A randomized trial now compares full-endoscopic decompression directly against conventional laminectomy, a level of evidence the field lacked a decade ago.6 Unilateral biportal endoscopy has developed into a distinct and mature body of practice, and endoscopic fusion has developed into a distinct procedural category. The 2020 framework was written for the procedures mature at that time; it now has to cover techniques that were only emerging then.

Why terminology is not a small matter

Naming is often treated as secondary to the clinical questions, to be settled once those are answered. It is not secondary. Terminology is the infrastructure of research, education, and communication, and an incomplete vocabulary carries a real and cumulative cost.
It shows up first in the literature. When the same procedure is published under several different names, systematic reviews and meta-analyses miss relevant studies or double-count them. Registries cannot pool outcomes that are recorded under inconsistent labels. A surgeon searching for evidence on a specific technique may never find half of what has been written about it, and a reader comparing two papers cannot always tell whether they describe the same operation or two different ones. As the volume of endoscopic spine publications continues to rise, this problem grows rather than shrinks.

The most visible symptom is the proliferation of acronyms. The same broad field is now navigated through UBE, BESS, FESS (full-endoscopic spine surgery), PELD, TELD, IELD, BE-TLIF, and Endo-TLIF, among many others; some name a mode of visualization, some an approach corridor, some a procedure, and some a mixture of all three. A reader cannot always tell from the acronym alone what was actually done, and databases and registries certainly cannot.

Training and credentialing suffer as well. It is hard to define competency in a procedure that different programs describe in different words, or to build fair assessment on an unsettled vocabulary, and a trainee who learns one set of terms in one center may find the same steps renamed in the next. The patient is affected too: if we cannot describe our procedures consistently to one another, we cannot describe them clearly to those we operate on or to the physicians who refer them. Consistent terminology is a practical prerequisite for sound research, teaching, and consent.

Two areas that now need definition

The 2020 consensus did its work well for the procedures that were mature at the time, and its four-part logic of endoscope type, approach corridor, spinal segment, and procedure type remains a sound foundation. It placed biportal endoscopy within the endoscope-assisted category, alongside full-endoscopic procedures; the task now is to specify how biportal visualization maps onto the same four-part logic without collapsing it into a single residual label. Two areas have since grown beyond what a single early framework could capture, and both now deserve finer definition within that same logic.

Part of the difficulty is that three independent dimensions are often collapsed into a single name: the portal configuration (uniportal or biportal), the approach corridor (interlaminar, transforaminal, trans-Kambin, and so on), and the procedure performed (decompression, discectomy, or interbody fusion). These vary independently: a biportal, lumbar, interlaminar decompression and a uniportal, lumbar, transforaminal discectomy differ on every axis, yet an operation is frequently named by only one of them. Keeping these dimensions distinct is therefore central to a workable nomenclature. It also explains why UBE and endoscopic fusion present different nomenclature problems. Unilateral biportal endoscopy names a portal configuration, not a procedure; endoscopic fusion names a procedure category, not a mode of visualization.

The first is unilateral biportal endoscopy. By its two-portal design, UBE is not a working-channel, full-endoscopic technique. The 2020 consensus therefore placed it within the endoscope-assisted category, a reasonable classification at a stage when the technique was still little known. What has changed is scale: UBE has since matured into a large and distinct body of practice, with its own techniques, instruments, and rapidly expanding literature.4 It is now used across the cervical, thoracic, and lumbar spine, and across procedures that range from decompression and foraminotomy to laminectomy, reconstruction, and interbody fusion. Its complication profiles have been characterized in their own right, dedicated reviews now offer structured algorithms for managing events such as dural tears and bleeding, and the incidence and risk factors for early reoperation have been quantified, all of which are markers of a maturing discipline.

Comparisons against microscopic decompression, including a post-hoc analysis of a multicenter randomized trial in patients with concomitant grade I spondylolisthesis, place it on firmer evidentiary ground. The single “endoscope-assisted” label that was reasonable for a small, emerging technique in 2020 is now stretched across operations that differ meaningfully from one another. When a lumbar discectomy, a unilateral laminotomy for bilateral decompression, a cervical laminoplasty, and an interbody fusion are all reported simply as “UBE,” registries and meta-analyses lose the ability to compare like with like. The task is not to reclassify UBE as a full-endoscopic technique, but to give it the internal definition its scale now demands, so that the term captures the mode of visualization and the type of procedure with the same precision the consensus applied to uniportal work.

The second is endoscopic fusion. When the consensus was written, endoscopic fusion was only beginning to take shape, and the framework understandably centered on decompressive procedures. Fusion has since become an established procedure, and, importantly, it is now performed through both uniportal and biportal routes. This is what makes it more than a single new entry to be slotted into one branch. Fusion is a procedure category that cuts across the mode of visualization: the same reconstructive goal is reached through different endoscopic routes, with outcomes now reported against established anterior and minimally invasive techniques. 

A complete nomenclature has to let a fusion performed one way and a fusion performed another way be named, distinguished, and compared on consistent terms. It should also map onto the fusion vocabulary surgeons already use, so that an endoscopic TLIF sits recognizably alongside MIS-TLIF, ALIF, and other established interbody procedures rather than apart from them. Placing fusion cleanly within the “type of procedure” axis, while allowing it to be paired with either visualization mode, is a concrete example of how the 2020 structure can be extended rather than rebuilt.

In both cases it is the scope of the 2020 framework, not its quality, that has been outgrown. The framework holds; what it needs is to name biportal visualization and fusion with the same care it already applies to uniportal work.

What a unified nomenclature should do

If the field is going to revisit its terminology, it is worth being explicit about what a good nomenclature has to achieve. Four features matter: it should be descriptive, extensible, neutral, and interoperable.

Descriptive, so that a name conveys how the spine is approached, how it is visualized, which segment is treated, and what is done, rather than functioning as a brand. Extensible, because new techniques will keep appearing. Neutral, tied to no single company, school, or region, since a term that belongs to one interest will not be adopted by the others. And interoperable with the terms already in use and with coding and registry systems, so that adopting it does not orphan the existing literature. That last requirement is practical as much as academic: procedure coding and reimbursement, from CPT codes in the United States to their national counterparts, still lag behind endoscopic practice, and a nomenclature built with that mapping in mind will be easier to adopt.

Toward a single unifying anchor

Extending the vocabulary is necessary, but it is not enough on its own. If each technique and each region continues to add terms independently, the field will end up with more names, not clearer ones. What is needed is a single overarching anchor: one term that gathers uniportal, biportal, and fusion procedures under a common idea, so that the more detailed terms sit within one shared structure rather than competing with it.

The natural basis for such an anchor is the principle that all of these procedures share, which is endoscopic visualization of the surgical field. One term proposed in this spirit is spinoscope, suggested by Hyeun-Sung Kim (H.S. Kim) as an inclusive descriptor for the endoscope used across the spine, by analogy with the laparoscope; the corresponding procedural term, spinoscopy, would follow by analogy with laparoscopy. Other candidate umbrella terms have also been floated. Which term is ultimately adopted matters less than the idea they share: the field needs a common anchor that unites rather than divides, and the choice among candidates should rest with a multi-society process rather than any single group. Whatever term is chosen, it should respect the 2020 consensus as its foundation rather than setting it aside.

A path forward

A unified nomenclature cannot simply be imposed. If it comes from a single society, region, or author group, it will be read as one more competing proposal and is unlikely to be widely adopted. There is growing recognition that the field’s future depends on consensus rather than rivalry, and that a shared language is part of that shift. For this reason, the process should be as inclusive as the terminology itself. A system developed through broad community participation is more likely to gain acceptance across regions and societies.

The way forward is a broad, multi-society consensus that includes the regional endoscopic spine societies across Asia, Europe, and the Americas where these techniques are practiced and taught. Definitions can be proposed, tested against real cases, and revised until there is broad agreement. The aim is a shared structure that every group can adopt without giving up what is clinically meaningful in its own practice. This takes longer than simply publishing definitions, but it is what produces terminology surgeons actually use.

A call to converge

Endoscopic spine surgery is now part of mainstream practice; its terminology has not fully caught up. The 2020 consensus laid a solid foundation, and the task now is to complete it — to define the areas that have grown since and bring them under a common anchor — such as spinoscopy, the procedural counterpart of the proposed term spinoscope.

A formal, multi-society consensus effort to define and adopt this terminology is now being organized under AOSERG. We offer this Perspective as an invitation to take part in it.

Acknowledgments

The authors acknowledge Hyeun-Sung Kim for originally proposing the term spinoscope, from which the procedural term spinoscopy follows and which informs the unified nomenclature discussed here.

Declaration of Conflicting Interests

The authors declared the following potential conflicts of interest with respect to the research, authorship, and/or publication of this article: J.-S. Kim serves as a consultant for RIWOspine (Germany), Nexon Medical (Switzerland), and Elliquence (USA), outside the submitted work, and holds leadership roles within AO Spine as head of the AO Spine Endoscopic Research Group (AOSERG) and as a member of the AO Spine Knowledge Forum Degenerative Steering Committee. M.M. Taha holds leadership positions within the AO Spine Middle East and North Africa (MENA) Board and the SICOT Spine Subspecialty Committee. The remaining authors declare no conflicts of interest relevant to this work.

Funding

The authors received no financial support for the research, authorship, and/or publication of this article.

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